The LM5046 PWM controller contains all of the features necessary to implement a
phase-shifted full-bridge topology power converter using either current mode or voltage mode
control. This device is intended to operate on the primary side of an isolated DC-DC converter with
input voltage up to 100 V. This highly integrated controller-driver provides dual 2-A high- and
low-side gate drivers for the four external bridge MOSFETs, plus control signals for the
secondary-side synchronous rectifier MOSFETs. External resistors program the dead-time to enable
zero-volt switching of the primary FETs. Intelligent startup of the synchronous rectifiers allows
monotonic turnon of the power converter even with prebias load conditions. Additional features
include cycle-by-cycle current limiting, hiccup mode restart, programmable soft-start, synchronous
rectifier soft-start, and a 2-MHz capable oscillator with synchronization capability and thermal
shutdown.
- Highest Integration Controller for Small
Form Factor, High-Density Power Converters - High-Voltage Start-Up Regulator
- Intelligent Sync Rectifier Start-Up Allows
Linear Turn-on into Prebiased Loads - Synchronous Rectifiers Disabled in UVLO Mode
and Hiccup Mode - Two Independent, Programmable Dead-Time
Adjustments to Enable Zero-Volt Switching - Four High-Current 2-A Bridge Gate Drivers
- Wide-Bandwidth Opto-Coupler Interface
- Configurable for Either Current Mode or Voltage
Mode Control - Dual-Mode Overcurrent Protection
- Resistor Programmed 2-MHz Oscillator
- Programmable Line UVLO and OVP
| Topology | Phase-shifted full bridge |
| Control mode | Current |
| Duty cycle (max) (%) | 100 |
| Switching frequency (max) (kHz) | 1000 |
| Features | Adjustable switching frequency, Current limiting, Error amplifier, High-voltage startup, Integrated gate drivers, SR logic, Soft start, Soft switching |
| UVLO thresholds on/off (V) | Programmable/1.25V |
| Operating temperature range (°C) | -40 to 125 |
| Rating | Catalog |
| Gate drive (typ) (A) | 1.5, 2 |
| Vin (max) (V) | 14 |